Frame and screen construction for screen printing



Feb. '26, 1963 D. JAFFA ETAL 3,078,793

FRAME AND SCREEN CONSTRUCTION FOR SCREEN PRINTING Filed Jan. 12, 1962 2Sheets-Sheet 1 F|G.I FIG. 10

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H 24 14 /J=L INVENTORS Marthgw Jaffa- BY Davld Jaffa ATTORNEY Feb. 26,1963 D. JAFFA ETAL FRAME AND SCREEN CONSTRUCTION FOR SCREEN PRINTING 2Sheets-Sheet 2 Filed Jan. 12, 1962 FIG.7

United States Patent Ofifice 3,078,793 ?atented Feb. 26, 1963 3,673,793FRAME AND SCREEN CGNSTRUCTIUN FUR SCREEN PRINTKNG David Jafr'a, FairLawn, and Matthew L. Jaifa, Rutherford, N.J., assignors to PrecisionScreen Machines Co. inc, Hawthorne, N..!., a, corporation of New JerseyFiled Jan. 12, 1962, Ser. No. 165,922 19 Claims. (Cl. Hill-427.1)

. This invention relates in general to art of screen printing, and morespecifically to an improved screen frame construction and printingscreen therefor.

An object of this invention is to provide an improved frame constructionfor stretching a printing screen drum tight thereon.

Another object is to provide an improved screen frame constructionhaving novel means for adjusting any segment of a design in a screenstretched thereover and in any direction to improve the fit orregistration of one color to another during printing.

Still another object of the invention resides in an improved frame andscreen construction whereby the screen can be readily attached orremoved from the frame in a relatively simple and expedient manner.

A feature of this invention resides in the provision that the improvedframe construction and screen therefor are relatively simple inconstruction and positive in operation.

Still another feature resides in the provision whereby the frameconstruction'and screen permits removal of the screen after a printingoperation so that it can be rolled and stored, thus minimizing storageareas for the storing of such screens.

Other features and, advantages will become more readily apparent whenconsidered in view of the drawingsand description in which:

7 FIG. 1 isa top-plan view of the screen frame construction ofthisinventio n illustrated without screen.

FIG. 2 is an end view of the frame construction of FIG. 1 with screenattached. a

g FIG. 3 is a section view taken along line 33 of FIG. 2.

FIG. 4 is a detail plan view of the improved screen construction of thisinvention.

PEG. 5 is an enlarged sectional view taken along line 55 of FIG. 4.

FIG. 6 is a fragmentary side view of a modified frame construction asused with a wire screen.

FIG. 7 is a fragmentary sectional view of still another modified form ofthe invention.

FIG. 8 is a plan view of the head of an adjusting bolt.

F! G. 9 is a plan view of a modified bolt head.

- -FIG.-10 is a modified screen frame of the type illustrated in FIG. 1.

Referring to the drawings, the improved frame or screen stretchercomprises an inner frame 21 formed of rectangularly disposed frame side22 and end 23 members. Generally this inner frame 21 may be made of woodor other suitable material. Connected to the outer periphery of theinner frame 21 is an outer stretcher frame 24 as shown in FIGS. 1, 2 and3, the stretcher frame 24 including side and end sections 25, 26,respectively, connected to the outer surfaces of the corresponding sideand end members 22, 23 of the inner frame 21. Each of the stretcherframe sections 25, 26 comprise an angle member having a vertical andhorizontal leg or flange 27, 29, respectively. The vertical leg 27 ofeach outer frame section 25, 26 is connected to the outer periphery ofthe corresponding inner frame member by suitable fasteners such asscrews and the like. In the illustrated embodiment it will be noted thatthe inner frame members 22, 23 extend slightly beyond the ends of thestretcher frame sections 25, 26 connected thereto. As shown in FIG. 3,the

bottom of the vertical leg 27 portion is flush with the bottom of thecorresponding inner frame member.

The horizontal leg 29 of each section extends outwardly from the innerframe 21 and a plurality of marginal apertures or notches 3! are spacedlongitudinally along each of the horizontal flanges 29.

The screen 31 adapted to be stretched over the frame 21, is shown inFIGS. 4 and 5. Generally screen 31 may be formed either of silk or wiremesh depending on the nature of the printing to be performed. In eitherevent, the screen construction of this invention comprises a printingportion having looped hems 33 extending substantially co-extensive withthe respective sides of the printing portion.

In accordance with this invention the looped hem 33 along each side ofthe screen is formed by a tape 34 that is reversely folded, as seen inFIG. 5. Intermediate the width of the tape 34 and extendinglongitudinally thereof is a sewn seam 35 to secure the folds 34A and 34Btogether, the seam 35 and closed end of the tape defining therebetweenthe loop 36. Hem 33 is attached to the screen 31 by disposing the endportion of screen 31 between the free ends 37, 38 of tape 34.

As shown in H6. 5, a resin adhesive or other suitable thermoplasticbonding strip or agent 39 and the like may be disposed between each freeend 37, 38 of the tape 33 and the screen 31. Thus, with the applicationof heat and pressure over the ends of the tape, a firm connection is hadbetween the hem 33 and the screen portion 31.

In accordance with this invention the screen 31 is stretched andadjusted to the frame 21 described by a plurality of holding fixtures 4Gin a novel manner. As seen in FIGS. 2 and 3, each fixture 40 includesessentially a split collar 41 which is preferably formed as arectangular block having a split or C-shaped opening 42 adapted toreceive the looped hem 33 of the screen 31. Each block 41 also isprovided with a tapped hole 43 extending therethrough to one side of theopening 42.

A bolt 44 adapted to be threaded into the tapped hole 43 of the blockadjustably connects the block 41 to the frame 24. In accordance withthis invention, the bolt 44- of each fixture 49 is adapted to bereceived in one of the notches 36 of the stretch frame 24. As shown inFIG. 3, the flanges 29 of the stretch frame 24 and the split blocks 4dare each proportioned so that in the assembled position the blocks 41are disposed in sliding contact with the vertical leg 27 of therespective frame section 24.

Each bolt 44 is provided with an enlarged head portion 4-5 which isadapted to sit on the flanges 29 of the stretcher frame 24. If desired,a washer 46 may be interposed between the head 45 of the bolt and .theflange 29*. As shown in FIG. 8, the head 45 of each bolt 44 is providedwith a socket 47 for receiving a tool, e.g. an Allen wrench, by whichthe bolt 44 may be turned to effect adjustment of the split collar block41 relative to the frame 24. As an alternate construction the bolt 44Amay be formed with a hex head 45A and/or a combination of hex head andsocket 47A.

To secure the screen 31 to the frame 24, the looped end of the hem 33 isinserted into each of the openings 43 of the split collars 41 common toone side of frame 24. A retaining rod 48 is then inserted into the hem33 with-in the split collar 41. As shown in FIG. 3, it

.will be observed that the diameter of the rod 48 is larger collars 41accordingly, the fabric of the screen 3 1 is stretched tightly acrossthe bottom of the frame 21.

For the foregoing description it will be readily apparent that thescreen 31 can be readily attached and detached from the frame 24. Thusafter wash up and after the printing is completed, the respective rods48 may be removed from the hem 33 of the screen 3 1, and the screenbeing then removed may be rolled up for economical storage in a sealedtube. If desired, a number or a set of such screens may be rolled andstored in a single tube. Being able to remove the screen from its frameafter each printing operation avoids the possibility of screen sagresulting from maintaining the screen stretched on the frame forprolonged periods. When the design of a given screen is needed again, itbecomes a simple matter with the described construction to lay out theoriginal art work and remount each screen to a master frame and adjusteach to perfect register.

In the event it is desirable to utilize a wire cloth for a screeninstead of silk or nylon, the construction is similar to that hereindescribed, except that the free ends of the hem or hem tape are attachedto either side of the screen by either soldering or sewing. Also as seenin FIG. 6, a compression spring 50 is placed about the adjusting bolts5-1 between the head 51A and the flange 52 of the stretcher frame 53.Thus when the wire cloth is stretched over the frame 53 it will have atendency to be slightly resilient. The wire screen thus mounted, has thestability of wire together with the ability to resist pressure stretch.

FIG. 7 illustrates a modified frame section 60. In this form, the innerand outer frames are integrally formed in an extruded structural shapeas a continuous bar. Thus, to form the frame for a screen, the bar needonly be cut to length and assembled to form a rectangular closed figureof any suitable size.

As shown in FIG. 7 the extruded member is provided with an F-shapedcross-sectional shape 60. Essentially it consists of a horizontallydisposed back 61 having conn'e'cted thereto" an inner and outerdepending arm portion 62, 63, the former extending slightly beyond thelatter. The free end of each arm 62, 63 is provided with a roundedsurface 62A, 63A.

As with the stretcher frame segments of FIGS. 1 to 3, the laterallyextending portion 61A of the modified frame 60'is provided withapertured portions for receiving the adjusting bolt 44 of the splitcollar 41 in the manner as hereinbefore described.

Referring to FIG. 7 it will be noted that the face of the split collar41 is disposed in contacting relationship with the outer surface 63B ofthe outer arm 63. With the screen 65 assembled to the frame 60 in amanner as hereinbefore described, the length and end shapes of each arm62, 63 permit the extended ends of the screen to be guided thereoverWithout snagging, or catching. In all otherrespects, the construction ofthe holding fixtures and their particular mode of operation in this formof the invention is the same as that described with reference to FIGS. 2and 3. Therefore, the description thereof need not be repeated.

FIG. lOillustrates a modified frame construction 120 of the typedisclosed in FIG. 1. It comprises an inner frame composed of side andend members 122 and 123. Connected to the inner frame members 122 arethe angle members 125 of the outer frame. Members 125 are provided withspaced notches 130 as herein described with reference to FIG. 1. In thisform the end members of the outer framesare omitted. In all otherrespects the operation and construction thereof is similar to that ofFIG. 1 herein, and need not be further described.

An important feature of this invention resides in the provision that theretaining rod 48 is flexible, i.e. it is free to flex in the event oneof the split collars 41 spaced therealong is tightened more or less thanthe next adjacent collar. For this reason portions of the screen 4 maybe adjusted or stretched independently of other portions thereof. Thusthe ability of the rod 48 to flex under certain conditions greatlyenhances the adjustability or orientation of the screen.

While the instant invention has been disclosed with reference to aparticular embodiment thereof, it is to be appreciated that theinvention is not to be taken as limited to all of the details thereof asmodifications and variations thereof may be made without departing fromthe spirit or scope of the invention.

What is claimed is:

l. A stencil comprising an inner frame, an outer stretcher frameconnected to the outer periphery of said inner frame, said outer frameconsisting of an angle having a vertical and horizontal leg portions,means connecting the vertical leg portion of said stretcher frame to theinner' frame so that the horizontal leg portion extends laterallyoutwardly of the connected inner frame member, said stretcher framehaving a plurality of notches spaced therearound, a printing screenadapted to be stretched over said inner frame, said screen having loopedhem portions about the periphery thereof, and a holding fixture locatedat each of the notches spaced along the stretcher frame for securing andstretching said screen over said inner frame, each of said holdingfixtures including a split collar' block adapted to receive the hem ofthe screen, a holding rod extended through the looped hem within thecollar blocks spaced along the side of said stretcher frame forretaining the hem in position within said collar blocks, and adjustingmeans for securing each of the collar blocks to the stretcher frame,said latter means including a threaded bolt adapted to engage a threadedbore in said collar block whereby said screen is stretched and adjustedby tightening and loosening the bolts accordingly to raise and lower therespective blocks independently of one another.

2. The invention as defined in claim 1, wherein said split c'ollar blockis disposed in sliding engagement with the vertical leg of the stretcherframe.

3. A stencil comprising an inner frame, an outer stretcher frameconnected to the outer periphery of each of said inner frames, saidouter frame consisting of an angle bar having a vertical and horizontalleg portion, means connecting the vertical leg portion of said outerframe to the inner frame with the horizontal leg portion extendinglaterally outwardly of the connected inner frame member, said stretcherframe having a plurality of notches spaced therearound, a wire screenadapted to be stretched over said inner frame, said screen having loopedhem portions about the periphery thereof, and holding fixtures locatedat each of the notches spaced along the outer frame for securing andstretching said wire screen over said inner frame, each of said holdingfixtures including a split collar block adapted toreceive the hem of thescreen, a holding rod extending through the looped hem within eachcollar block spaced along a side of said stretcher frame for retainingthe hem in position within said collar blocks, adjusting means forsecuring each of the collar blocks to the outer frame, said latter meansincluding a headed bolt adapted to engage a threaded bore in said collarblock whereby said screen is stretched and adjusted by tightening andloosening the bolts accordingly to raise and lower the respective blocksindependently of one another, and a spring disposed between the head ofthe bolt and horizontal leg of the outer frame to impart resiliency tosaid screen.

4. A stencil comprising an inner frame including rectangularly' disposedside and end members, an outer stretcher frame connected to the outerperiphery of each of said side and end members, said stretcher frameincluding side and end sections connected to the corresponding side andend members of said inner frame, each of said stretcher frame sectionsincluding an angle bar having a vertical and horizontal leg portion,means connecting the vertical leg portion of each stretcher framesecapropos tion to the corresponding member of said inner frame so thatthe horizontal leg portion extends laterally outwardly from theconnected inner frame member, each of said stretcher frame sectionshaving a plurality of spaced notches formed therein, a screen containingthe stencil design adapted to be stretched over said inner frame, saidscreen having looped hem portions about the periphery thereof, andholding fixtures located at each of the notches spaced along thestretcher frame sections for securing and stretching said screen oversaid inner frame, each of said holding fixtures including a split collarblock adapted to receive the hem of the screen, a holding rod extendedthrough the looped hem Within each collar block spaced along eachstretcher frame section for retaining the hem in position therein, andadjusting means including a threaded bolt adapted to engage a threadedbore in said collar block whereby said screen is stretched and adjustedby tightening and loosening the bolts accordingly to raise and lower theblocks independently of one another.

5. A stencil comprising a stretcher frame comprising rectangularlydisposed side and end frame segments, each of said segments including anintegrally formed spaced depending inner and outer arm portion, each ofsaid arm portions having a rounded end, and said inner arm portion beinglonger than the outer arm portion, a screen lnving looped hems stretchedover the depending arm portions, and a plurality of holding fixtures forstretching and adjusting said screen to said frame, said holdingfixtures being spaced about the periphery of said frame, each fixtureincluding a split block having an opening therein, means for securingthe hem of said screen in the opening of said blocks, and an adjustingbolt connecting said split block to said frame whereby said screen canbe stretched and adjusted by the respective adjustments of theindividual collar blocks.

6. A stencil comprising a stretcher frame comprising rectangularlydisposed side and end frame segments, each of said segments including anextruded structure having integrally formed spaced depending inner andouter arm portions, each of said arm portions having a rounded end, andsaid inner arm portion being longer than the outer arm portion, saidsegment extending laterally from said outer arm portion, a screen havinglooped hems stretched over the depending arm portions of said frame, anda plurality of holding fixtures for stretching and adjusting said screento said frame, said holding fixtures being spaced along the extendedportion of said segments about the periphery of said frame, each fixtureincluding a split block having an opening therein, said block beingdisposed in sliding engagement with the surface of the outer armportion, means for securing the hem of said screen in the opening ofsaid blocks, and an adjusting bolt connecting said split block to theextended portion of said frame whereby said screen can be stretched andadjusted by the respective adjustments of the individual collar blocks.

7. An improved stenciling screen comprising a rectangular screen portionand a looped hem extending about each side of the said screen portion,said looped hem terminating short of the corner portions of said sidesand including a reversely folded tape, a sewn seam connecting thereverse folds of said tape only intermediate the width thereof to definethe loop and means connecting the free ends of said tape to both sidesof the design portion of said screen.

8. An improved stenciling screen comprising a rectangular screen portionand a looped hem extending about each side of the said screen portion,said hem terminating short of the ends of the sides of said screen, andsaid looped hem including a reversely folded tape, a sewn seamconnecting the reverse folds of said tape only intermediate the widththereof to define the loop, and a resin strip disposed between each freeend of said tape and the screen disposed therebetween so that upon theapplication of heat and pressure said tape will be fused to said screenportion.

9. A stenciling screen comprising a rectangular stretcher frame, arectangular stenciling screen adapted to fit said frame, a looped hemconnected to each side of said screen, said frame having an outwardlyextending flange along each side thereof, and a plurality of separateand distinct holding fixtures connected to each of said flanges, each ofsaid fixtures including a collar block, said blocks being spaced onefrom the other along their respective flanges, and each block having aC- shaped opening adapted to receive the looped hem of said screen, arod fitted through the looped hem of said screen within said openings ofsaid blocks for retaining the screen therein, and a single adjustingbolt for connesting and adjusting each of said blocks to theirrespective flanges whereby said screen is stretched and adjusted by theadjustments of said bolts accordingly to raise and lower the respectiveblocks independently of one another.

10. A stenciling screen comprising a rectangular stretcher frame, arectangular stenciling screen adapted to fit said frame, said screenhaving a looped hem connected along each side of said screen, said framehaving an outwardly extending flange along each side thereof, and aplurality of separate and distinct holding fixtures spaced along theflange of each side of said frame, each of said fixtures including aspiit collar block, each of said blocks having a split opening adaptedto receive the looped hem of said screen, a rod fitted through thelooped hem along each side of said screen within said blocks spacedalong the flange of the adjacent side of said frame for retaining thescreen therein, said rod having a diameter greater than the split ofsaid opening, and a single adjusting bolt for connecting and adjustingeach of said blocks to said flange whereby said screen is stretched andadjusted by adjusting said bolts accordingly to adjust the respectiveblocks independently of one another, said bolt having an enlarged head,and a spring disposed between the flange and head of said bolt to rendersaid screen resilient.

References Cited in the file of this patent UNITED STATES PATENTS629,916 North Aug. 1, 1899 890,759 Dick June 16, 1908 1,350,488 BlaineAug. 24, 1920 1,734,287 Cornell Nov. 5, 1929 1,835,931 Chesley Dec. 8,1931 1,892,268 Glockhart Dec. 27, 1932 2,218,451 Heyne Oct. 15, 19402,566,919 Black et a1. Sept. 4, 1951 2,854,922 Leibenguth Oct. 7, 19582,903,967 Levin Sept. 15, 1959 2,988,457 Gatcomb June 13, 1961 FOREIGNPATENTS 615,791 Great Britain Jan. 11, 1949 718,839 Germany Mar. 21,1942

9. A STENCILING SCREEN COMPRISING A RECTANGULAR STRETCHER FRAME, ARECTANGULAR STENCILING SCREEN ADAPTED TO FIT SAID FRAME, A LOOPED HEMCONNECTED TO EACH SIDE OF SAID SCREEN, SAID FRAME HAVING AN OUTWARDLYEXTENDING FLANGE ALONG EACH SIDE THEREOF, AND A PLURALITY OF SEPARATEAND DISTINCT HOLDING FIXTURES CONNECTED TO EACH OF SAID FLANGES, EACH OFSAID FIXTURES INCLUDING A COLLAR BLOCK, SAID BLOCKS BEING SPACED ONEFROM THE OTHER ALONG THEIR RESPECTIVE FLANGES, AND EACH BLOCK HAVING ACSHAPED OPENING ADAPTED TO RECEIVE THE LOOPED HEM OF SAID SCREEN, A RODFITTED THROUGH THE LOOPED HEM OF SAID